You might get farther if you searched for "user variable" as well as "wildcard"? and/or tried the Word for Mac forum. Can't find the address, unfortunately; the search on this forum rejects 'mac' as too short or too common to be a search term …

Never used Word on a Mac, but what you seem to be trying for is just including a document property field in the footer (or elsewhere in the document). Word for Windows has a shortcut to force the updating of all fields, and an option to update all fields before printing.